public RateLimitCounter ProcessRequest(ClientRequestIdentity requestIdentity, RateLimitOptions option)
{
RateLimitCounter counter = new RateLimitCounter(DateTime.UtcNow, 1);
var rule = option.RateLimitRule;
var counterId = ComputeCounterKey(requestIdentity, option);
// serial reads and writes
lock (_processLocker)
{
var entry = _counterHandler.Get(counterId);
if (entry.HasValue)
{
// entry has not expired
if (entry.Value.Timestamp + TimeSpan.FromSeconds(rule.PeriodTimespan) >= DateTime.UtcNow)
{
// increment request count
var totalRequests = entry.Value.TotalRequests + 1;
// deep copy
counter = new RateLimitCounter(entry.Value.Timestamp, totalRequests);
}
}
// stores: id (string) - timestamp (datetime) - total_requests (long)
_counterHandler.Set(counterId, counter, TimeSpan.FromSeconds(rule.PeriodTimespan));
}
return(counter);
}
private RateLimitCounter GetCounter(string counterKey, RateLimitRule rule)
{
var counter = new RateLimitCounter
{
Timestamp = DateTime.UtcNow,
Count = 1
};
var entry = _rateLimitCounterHandler.Get(counterKey);
if (entry.HasValue)
{
// entry has not expired
if (entry.Value.Timestamp + rule.PeriodTimespan.Value >= DateTime.UtcNow)
{
// increment request count
var totalRequests = entry.Value.Count + 1;
// deep copy
counter = new RateLimitCounter
{
Timestamp = entry.Value.Timestamp,
Count = totalRequests
};
}
}
return(counter);
}
public RateLimitCounter ProcessRequest(ClientRequestIdentity requestIdentity, RateLimitOptions option)
{
RateLimitCounter counter = new RateLimitCounter(DateTime.UtcNow, 1);
var rule = option.RateLimitRule;
var counterId = ComputeCounterKey(requestIdentity, option);
// serial reads and writes
lock (_processLocker)
{
var entry = _counterHandler.Get(counterId);
if (entry.HasValue)
{
// entry has not expired
if (entry.Value.Timestamp + TimeSpan.FromSeconds(rule.PeriodTimespan) >= DateTime.UtcNow)
{
// increment request count
var totalRequests = entry.Value.TotalRequests + 1;
// deep copy
counter = new RateLimitCounter(entry.Value.Timestamp, totalRequests);
}
}
}
if (counter.TotalRequests > rule.Limit)
{
var retryAfter = RetryAfterFrom(counter.Timestamp, rule);
if (retryAfter > 0)
{
var expirationTime = TimeSpan.FromSeconds(rule.PeriodTimespan);
_counterHandler.Set(counterId, counter, expirationTime);
}
else
{
_counterHandler.Remove(counterId);
}
}
else
{
var expirationTime = ConvertToTimeSpan(rule.Period);
_counterHandler.Set(counterId, counter, expirationTime);
}
return(counter);
}